A communication terminal that is compatible with WLAN (Wireless Local Area Network) wireless communication employed in high speed data communication is required to smoothly perform WLAN wireless communication after the communication terminal has entered a WLAN communication area.
For this reason, even when the communication terminal is in an area where it is difficult to carry out WLAN wireless communication (a WLAN communication-disabled area), power of a chip or a module used for carrying out WLAN wireless communication must be left on. This is one of factors that pose difficulty in diminishing power consumed by the communication terminal.
In recent years there is an increasing number of cases where a communication terminal compatible with WLAN wireless communication is equipped with a Bluetooth (registered trademark) wireless system used for a link, with peripheral devices, including a wireless headphone, a keyboard, and a mouse. Bluetooth wireless communication generally involves consumption of a smaller amount of current when compared with WLAN wireless communication.
When the communication terminal is in the WLAN communication-disabled area, the power consumed by the communication terminal can be reduced, so long as the communication terminal stays on standby in the Bluetooth wireless system while the power of the chip or the module for WLAN wireless communication is turned off.
Although a method for switching between the wireless communication systems is not specifically mentioned, Patent Literature 1 discloses employing an appropriate wireless communication system from one use to another.
FIG. 6 is a diagram showing communication between related-art heterogeneous communication devices compatible with both WLAN wireless communication and Bluetooth wireless communication. As shown in FIG. 6, heterogeneous communication devices 501 and 506, having a relation one acting as a mobile station and the other acting as a base station, each include a communication interface compatible with WLAN wireless communication and another communication interface compatible with Bluetooth wireless communication.
The heterogeneous communication devices 501 and 506 use the appropriate communication interfaces from one use to another, thereby curbing the power consumed by the WLAN wireless communication interface and performing communication, as necessary, while assuring a rate WLAN communication.
Patent Literature 2 discloses a wireless terminal having a millimeter-wave transceiver and a microwave transceiver. According to the descriptions of Patent Literature 2, the term “millimeter wave” means electromagnetic waves in a frequency band of 30 GHz or more and less than 300 GHz. The millimeter-wave transceiver is an electromagnetic wave transceiver circuit using: for instance, 57 to 66 GHz bands.
In the meantime, the microwave means electromagnetic waves having a frequency band of 300 MHz or more and less than 30 GHz. The microwave transceiver is an electromagnetic wave transceiver circuit using; for instance, a 5 GHz band or a 2.4 GHz band. The wireless terminal stores as a correlation table correlation information about wireless links between a millimeter wave and a microwave which have different frequency bands. Based on received electric field intensity (RSSI) acquired during microwave communication, a determination is made as to whether or not millimeter-wave communication is enabled.